The brides-to-be bond over their rings. Plus: Uma Thurman, Kevin Federline and more

ALL THAT GLITTERS ...

Newly engaged gals Christina Aguilera and Nicole Richie show off their sparklers at the opening of designer Roberto Cavalli's Beverly Hills store on Tuesday. Aguilera's fiancé, Jordan Bratman, gave her a diamond-and-platinum ring from London jewelry designer Steven Webster (whose clients have included Madonna and Jennifer Lopez), while Richie's betrothed, Adam Goldstein, gave her a pink sapphire rock.